Without limiting the scope of the present invention, its background is described with reference to providing communication and sensing during a production operation within a subterranean wellbore environment, as an example. It is well known in the subterranean well completion and production arts that downhole sensors can be used to monitor a variety of parameters in the wellbore environment. For example, during production operations, it may be desirable to monitor a variety of downhole parameters such as temperatures, pressures, pH, flowrates and the like in a variety of downhole locations. Transmission of this information to the surface may then allow the operator to modify and optimize the production operations. One way to transmit this information to the surface is using energy conductors such as electrical wires, optical fibers or the like.
In addition or as an alternative to operating as an energy conductor, optical fibers may serve as a sensor. For example, an optical fiber may be used to obtain distributed measurements representing a parameter along the entire length of the fiber. Specifically, optical fibers have been used for distributed downhole temperature sensing, which provides a more complete temperature profile as compared to discrete temperature sensors. In operation, once an optical fiber is installed in the well, a pulse of laser light is sent along the fiber. As the light travels down the fiber, portions of the light are backscattered to the surface due to the optical properties of the fiber. The backscattered light has a slightly shifted frequency such that it provides information that is used to determine the temperature at the point in the fiber where the backscatter originated. As the speed of light is constant, the distance from the surface to the point where the backscatter originated can also be determined. In this manner, continuous monitoring of the backscattered light will provide temperature profile information for the entire length of the fiber.
Use of an optical fiber for distributed downhole temperature sensing may be highly beneficial during production operations. For example, a distributed temperature profile may be used in determining the location of water or gas influx. Likewise, a distributed temperature profile may be used in determining the location of a failed gravel pack. It has been found, however, that installation of a completion including downhole sensors and energy conductors in a multi zone well requires numerous trips into and out of the well. In addition, it has been found, that even after the sensors and energy conductors have been installed and are providing information relative to production, well intervention may be required to modify or optimize the production operations.
Therefore, a need has arisen for an improved completion assembly that is operable to monitor a variety of downhole parameters in a variety of downhole locations. A need has also arisen for such an improved completion assembly that does not require numerous trips into and out of the well for multi zone installations. Further, a need has arisen for such an improved completion assembly that does not require well intervention to modify or optimize the production operations following receipt of information from the downhole sensors.